I love the idea of this plugin, and have been building some other PWA stuff - I was using this on a fairly big site, bought the pro version for $250 or around there, and have a couple issues, and have contacted them 4 or 5 times with no response. Super cool when it works, but a few small but important issues (like code showing up in headlines and no search feature...really?) went unanswered so I uninstalled and now consider it a waste of money. Too bad...PWAs are the stuff of the future and I love the way this works, but I'm seriously disappointed in the lack of company response to my issues.
I give the two stars for the design and basic function, but -3 for the support. If they got these couple small issues ironed out I would reinstall and give 5-stars easily...but they must have bigger fish to fry.